The present invention relates to an encoding system for subband coding of a wideband digital signal, for example, a digital signal having a specific sampling frequency F.sub.s. The encoding system comprises: (a) a splitter which divides the bandwidth of the wideband digital signal into M successive subbands which augment with frequency, and generates, in response to the wideband digital signal, M subband signals with sampling frequency reduction, each of the subband signals being associated with one of the subbands; (b) a quantizer unit for quantizing block-by-block the respective subband signals, a subband signal SB.sub.m of the subband signals being composed of successive signal blocks, each signal block comprising q samples, the q samples in a quantized signal block of subband signal SB.sub.m each being represented by n.sub.m bits; (c) a bit need determiner for determining bit needs for corresponding (i.e., time-equivalent) signal blocks of the subband signals, a signal block of subband signal SB.sub.m having a bit need b.sub.m which is related to the number of bits by which the q samples in that signal block should be represented; and (d) a bit allocator for allocating bits from an available quantity of bits B to the samples in the time-equivalent signal blocks of the subband signals in response to the bit needs determined by the bit need determiner, such allocation establishing the value of n.sub.m ; where 1.ltoreq.m.ltoreq.M. The encoding system may further comprise a formatting circuit for assembling the quantized samples of the time-equivalent signal blocks to form an output signal having successive frames and including scale factor information in each frame, which scale factor information comprises x-bit words, an x-bit word representing a scale factor associated with the samples in a signal block. An encoding system of the aforementioned type is known from U.S. Pat. No. 4,896,362.